Endovascular Coils as Lung Tumor Fiducial Markers for Real-Time Tumor Tracking in Stereotactic Body Radiotherapy: Comparison of Complication Rates with Transthoracic Fiducial Marker Placement

Purpose: To evaluate safety of endovascular coil fiducial placement and compare complication rates with transthoracic fiducial placement in patients with peripheral early-stage lung cancer receiving fiducial markers for stereotactic body radiotherapy (SBRT). Materials and Methods: This retrospective study included consecutive patients who received endovascular coils (n = 416 patients, n = 1,335 coils) or transthoracic fiducials (n = 30 patients, n = 80 fiducials) for SBRT between August 2005 and January 2017. During the first 3 years of the study period, patients preferentially received cylindrical platinum fiducial markers by percutaneous transthoracic placement; only patients with contraindications received endovascular coils. Thereafter, patients received endovascular fiducials as the first-line procedure. Endovascular embolization coils were placed via the femoral vein into subsegmental pulmonary artery branches near the tumor. Complications were scored by SIR criteria. Results: The success rate of endovascular coil placement was 99.8%. One patient developed grade 2 hemoptysis requiring procedure discontinuation. Following placement, 1 patient (0.2%) developed grade 3 cardiac arrhythmia. A total of 36 patients (9%) developed grade 1 complications: mild hemoptysis (n = 4; 1%), small asymptomatic pulmonary infarction or hemorrhage (n = 30; 7%), hypoglycemia (n = 1; 0.2%), and vasovagal episode (n = 1; 0.2%). Following transthoracic marker placement, 4 patients (13%) developed a pneumothorax requiring hospital admission and chest tube (grade 2), 6 patients (20%) developed pneumothorax requiring no intervention (grade 1), 2 patients (7%) experienced asymptomatic pulmonary bleeding, and 1 patient (3%) developed persistent pain. Conclusions: Endovascular coil fiducial placement for lung SBRT is associated with high procedural success rates and lower rates of clinically relevant complications than transthoracic marker placement.